1. Field of the Invention
The present invention relates to a battery comprising a cathode, an anode, and an electrolyte.
2. Description of the Related Art
In recent years, many portable electronic devices such as a mobile phone and a laptop computer have been introduced. Downsizing and weight saving of these devices have been made. Along with these situations, as a portable power source for these electronic devices, a lithium ion secondary battery has attracted attention. Improvement of characteristics of the lithium ion secondary battery has been desired.
Therefore, recently, it has been reported that characteristics of the lithium ion secondary battery have been improved by using an electrolyte wherein ethylene carbonate or propylene carbonate which is electrochemically stable and has a high dielectric constant is used as a main solvent, and a low viscosity solvent having a superior ion conductivity such as dimethyl carbonate is thereto mixed (for example, refer to Japanese Unexamined Patent Application Publication No. H02-172162).
However, in the battery using this electrolyte, there has been a problem that its capacity deteriorates during the initial charge, and its capacity deteriorates after repeating high load charge and discharge.